Preparation and application of YAG transparent ceramic suspension for plasma spraying

Abstract

The invention discloses preparation and application of YAG transparent ceramic suspension for plasma spraying, Y2O3 powder with high purity of 99.99% is selected to be prepared into slurry, the slurry is ball-milled, centrifuged, dried and sieved to obtain Y2O3 powder, the obtained Y2O3 powder and Al2O3 powder with high purity of 99.99% are weighed according to a stoichiometric ratio of Y3Al5O12 to prepare mixed slurry, spray granulation, calcination, dry grinding and sieving are carried out, and the YAG transparent ceramic suspension for plasma spraying is obtained. And the obtained powder is prepared into suspension liquid for plasma spraying. The YAG transparent ceramic serves as a plasma spraying coating, is high in hardness and can effectively resist scraping and abrasion of external objects, the abrasion resistance of the surfaces of the coated objects is enhanced, and the service life is prolonged. The supersonic plasma spraying technology is adopted, preparation of the YAG transparent ceramic coating which is high in density, low in porosity, uniform in structure and high in hardness is achieved, and physical and chemical reactions occurring in the long-term service process of the Y2O3 coating material are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of advanced ceramic preparation, and in particular relates to the preparation and application of a YAG transparent ceramic suspension for plasma spraying. Background Art

[0002] At present, the fine processing of semiconductor materials is a process that uses plasma etching technology to transfer fine patterns in ultra-large-scale integrated circuit production from photolithography templates to silicon wafers. It has high-fidelity characteristics and can achieve clear circuit patterns at the micron level. During the plasma etching process, fluorine-containing etching mixed gases such as CF4, CHF3, C4F6, O2 and Cl2 will cause problems such as surface splitting, contamination and increased surface roughness of other parts in the etching chamber, which seriously restricts the stability of the product. In addition, as the plasma etching power increases, the service performance requirements for parts in the etching chamber are getting higher and higher. The etching resistance solution of traditional anodized aluminum alloy can no longer meet the needs of the equipment. It is urgent to spray a new generation of plasma etching resistant coating on the surface of the parts to improve the stability and service characteristics of the equipment.

[0003] In order to solve the above problems, CN118851799A discloses a method for preparing and applying a multilayer silicon carbide etching material, which utilizes the high purity and high density of the silicon carbide etching body material, forms an etching body material with multiple interface layers through multilayer spraying, and realizes its long-term operation in the equipment. However, this method cannot be used for spraying other materials. CN118755288A discloses an alumina suspension for plasma spraying and its preparation method and application, which uses an alumina suspension for spraying, solving the technical problem of the suspension being difficult to store stably; however, the alumina crystal phase structure is unstable, the thermal erosion resistance is poor, and the service performance is unstable. Chinese scholars Ma Wen and others have found that Y2O3 has excellent chemical stability and heat resistance, which meets the use requirements of etching-resistant coating materials. However, there are physical and chemical reactions between the Y2O3 coating and the mixed plasma gas composed of CF4 / Ar / O2, which affects the service life of the coating. Summary of the invention

[0004] The present invention uses high-purity Y2O3 powder and high-purity Al2O3 powder as raw materials to prepare a suspension for plasma spraying, and adopts SPS (Supersonic Plasma Spraying) process to achieve the preparation of YAG transparent ceramic coating with high density, low porosity, uniform structure and high hardness, thereby avoiding physical and chemical reactions that occur in the long-term service process of Y2O3 coating materials.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] On the one hand, the present invention provides a method for preparing a YAG transparent ceramic suspension for plasma spraying, which specifically comprises the following steps:

[0007] ① Prepare commercial high-purity 99.99% micron Y2O3 powder into a slurry with a solid content of 14.0 vol.% to 16.0 vol.%, use a polyacrylic acid anion dispersant, and then perform ball milling;

[0008] ② Centrifuge the slurry obtained in step ①, remove the suspension, add deionized water, and stir using a high-speed stirrer;

[0009] ③ Centrifuge the slurry obtained in step ② twice, dry the wet material after removing the suspension, sieve and calcine;

[0010] ④ Mix the Y2O3 powder obtained in step ③ with commercial high-purity 99.99% Al2O3 powder according to the stoichiometric ratio of Y3Al5O 12 Weighing, using anhydrous ethanol as solvent, polyethyleneimine as dispersant, the amount of dispersant added is 0.1wt.% to 0.5wt.% of the total mass of Y2O3 powder and Al2O3 powder, adjusting the solid content of the slurry to 35wt.% to 40wt.%, ball milling for 15h to 30h, then adding 3wt.% to 6wt.% of PVB of the total mass of Y2O3 powder and Al2O3 powder, and continuing ball milling for 12h to 15h;

[0011] ⑤ The slurry obtained in step ④ is subjected to spray granulation, the granulation atomization speed is 8000r / min, the hot air temperature is 85℃~90℃, and Y2O3-Al2O3 spherical powder is obtained; sieve to obtain high fluidity powder;

[0012] ⑥ Calcine the powder obtained in step ⑤, dry grind the powder, and sieve it; then use an ultrasonic vibration screen to classify it, and take powder above 325 mesh for subsequent plasma spraying;

[0013] ⑦ The powder obtained in step ⑥ is prepared into a suspension, wherein the suspension has a solid content of 10 vol.% to 13 vol.%, and an ammonium polyacrylate dispersant is added to obtain the product;

[0014] Preferably, the amount of dispersant added in step ① is 0.5wt.% to 2.0wt.% of the mass of Y2O3 powder, the planetary ball milling medium is alumina grinding balls, the ball milling jar material is a high-purity alumina ball milling jar, the solvent is deionized water, the ball milling speed is 200r / min to 280r / min, and the ball milling time is 36h to 48h.

[0015] Preferably, in step ②, the centrifugal speed is 2400r / min~3000r / min, the centrifugal time is 5min~8min, the amount of deionized water added is 25wt.%~30wt.% of the mass of Y2O3 powder, the mixer speed is 4000r / min~6000r / min, and the stirring is 2h~4h.

[0016] Preferably, the drying temperature in step ③ is 55°C, the sieving is performed using a 100-mesh sieve 3 times, the calcination process is performed in an oxygen environment, the calcination heating rate is 3-5°C / min, the calcination temperature is 600°C-800°C, and the heat preservation is performed for 6h-8h.

[0017] Preferably, the amount of dispersant added in step ④ is 0.1wt.% to 0.5wt.% of the total mass of Y2O3 powder and Al2O3 powder, the planetary ball mill speed is 160r / min to 180r / min, PVB is a low viscosity type, model B-98, and is in powder form.

[0018] Preferably, the sieving in step ⑤ uses a 200-mesh sieve.

[0019] Preferably, the calcination environment in step ⑥ is an air environment, the calcination temperature is 1000° C. to 1020° C., the temperature is kept for 4 h to 8 h, alumina grinding balls are used for grinding, the sieve mesh number is 100 mesh, and the sieving is performed 3 times.

[0020] Preferably, the amount of the dispersant added in step ⑦ is 0.5wt.% to 1.0wt.% of the powder mass.

[0021] On the other hand, the present invention provides the use of the suspension prepared by the above preparation method in plasma spraying. The plasma spraying process is: the spraying gas is a mixed gas of argon, nitrogen and hydrogen, the total gas intake is 180-250slpm, the spraying current is 200A-280A, the atomizing gas flow rate is 30-60ml / min, and the spray gun moving speed is 500-800mm / s.

[0022] Preferably, the ratio of argon:nitrogen:hydrogen in the mixed gas is 5+x:4-xy:1+y, wherein: 1≤x≤3, 0≤y≤0.5, and argon, nitrogen and hydrogen are introduced synchronously.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention uses YAG transparent ceramic as a plasma spray coating, which has the high hardness of YAG transparent ceramic itself. The hardness of the coating obtained by plasma spraying using its suspension is also high, which can effectively resist scratches and abrasions from external objects, enhance the wear resistance of the surface of the coated object, and extend the service life. In addition, YAG transparent ceramic has excellent heat resistance and can remain stable under high temperature environments. The YAG ceramic coating formed by plasma spraying can withstand higher temperatures. When used in high-temperature working environments, such as on hot end components such as aircraft engines and gas turbines, it can effectively protect the base material and prevent it from deformation, damage, and other problems due to high temperature.

[0025] 2. Compared with the existing Y2O3 coating (Y2O3+3CF2*→2YF3↑+3CO↑), the present invention has stronger chemical inertness, does not react with fluorine-containing gases, and prolongs the service life of the etching chamber. In addition, YAG itself does not react chemically with acids and alkalis. When facing corrosive media such as acids, alkalis, and salts, the YAG ceramic coating can provide good protection for the base material to prevent the base from being corroded. It can be used for equipment surface protection in corrosive environments such as chemical and marine environments. In addition, since YAG transparent ceramics have high optical transmittance, although the light transmittance of the coating will be relatively reduced after plasma spraying, it still maintains a certain light transmittance property, which is unique in some special application scenarios that have certain requirements for optical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 SEM image of the powder prepared in step ⑥ of Example 1.

[0027] Figure 2 A single-particle magnified SEM image of the powder prepared in step ⑥ of Example 1.

[0028] Figure 3 SEM image and EDS spectrum of the surface after spraying of Example 1. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] ① Commercial high-purity 99.99% micron Y2O3 powder was prepared into a slurry with a solid content of 14.1 vol.%, and a polyacrylic acid anion dispersant was used. The amount of the dispersant added was 0.5 wt.% of the Y2O3 powder mass, and then planetary ball milling was performed. The ball milling medium was alumina grinding balls, the ball milling jar was an alumina ball milling jar, the solvent was deionized water, the ball milling speed was 200 r / min, and the ball milling time was 36 h;

[0032] ② Centrifuge the slurry obtained in step ① at a centrifugal speed of 3000 r / min for 5 min, remove the suspension, then add deionized water with a mass percentage of 25 wt.% of Y2O3 powder, and stir with a high-speed stirrer at a stirring speed of 4000 r / min for 2 h;

[0033] ③ Centrifuge the slurry obtained in step ②, repeat 2 times, dry the wet material after removing the suspension, the drying temperature is 55°C, sieve the dried material, sieve it 3 times with a 100-mesh sieve, and then calcine the obtained powder, the calcination atmosphere is oxygen, the heating rate is 3°C / min, the calcination temperature is 600°C, and keep warm for 6h;

[0034] ④ Mix the Y2O3 powder obtained in step ③ with commercial high-purity 99.99% Al2O3 powder according to the stoichiometric ratio of Y3Al5O 12 Weighing, using anhydrous ethanol as solvent, polyethyleneimine as dispersant, the amount of dispersant added is 0.1wt.% of the total mass of Y2O3 powder and Al2O3 powder, adjusting the slurry mass solid content to 35wt.%, and then planetary ball milling, the planetary ball milling speed is 160r / min, the ball milling time is 15h, and then adding powdered PVB B-98 with a total mass of 3wt.% of Y2O3 powder and Al2O3 powder, and continue ball milling for 12h;

[0035] ⑤ The slurry obtained in step ④ is subjected to spray granulation, the granulation atomization speed is 8000r / min, the hot air temperature is 90°C, and Y2O3-Al2O3 spherical powder is obtained; it is sieved using a 200-mesh sieve to obtain a high-fluidity powder;

[0036] ⑥ The powder obtained in step ⑤ was calcined in an air environment at a calcination temperature of 1000°C for 4 hours, and the obtained powder was dry-milled using alumina grinding balls, and then sieved with a 100-mesh sieve for 3 times; then the powder was graded using an ultrasonic vibrating sieve, and powders above 325 mesh were taken for subsequent plasma spraying;

[0037] ⑦ The powder obtained in step ⑥ is prepared into a suspension, the suspension volume solid content is 10 vol.%, and ammonium polyacrylate is used as a dispersant, and the amount of the dispersant added is 0.5 wt.% of the powder mass;

[0038] ⑧ The suspension obtained in step ⑦ is used for plasma spraying to obtain a plasma sprayed product. The plasma spraying process is as follows: the spraying gas is a composite gas mixed with argon, nitrogen and hydrogen, the ratio of argon: nitrogen: hydrogen is 6:3:1, the gas is synchronously fed, the total air intake is 180slpm, the spraying current is 200A, the atomizing gas flow rate is 30ml / min, and the spray gun moving speed is 500mm / s.

[0039] Figure 1 This is a SEM image of the powder prepared in step ⑥ of Example 1. It can be seen from the image that the powder has good sphericity and the average particle size of the powder is less than 45 μm.

[0040] Figure 2 This is a single enlarged SEM image of the powder prepared in step ⑥ of Example 1. It can be seen from the image that the powder has good sphericity and the average particle size of the powder is less than 45 μm.

[0041] Figure 3 The SEM image and EDS spectrum of the surface after spraying of Example 1 show that yttrium oxide and aluminum oxide are evenly distributed.

[0042] Example 2

[0043] ① Commercial high-purity 99.99% micron Y2O3 powder was prepared into a slurry with a solid content of 16.0 vol.%, and a polyacrylic acid anion dispersant was used. The amount of the dispersant added was 2.0 wt.% of the Y2O3 powder mass, and then planetary ball milling was performed. The ball milling medium was alumina grinding balls, the ball milling jar was made of high-purity alumina ball milling jars, the solvent was deionized water, the ball milling speed was 280 r / min, and the ball milling time was 48 h;

[0044] ② Centrifuge the slurry obtained in step ① at a centrifugal speed of 3000 r / min for 8 min, remove the suspension, then add deionized water with a mass percentage of 30 wt.% of Y2O3 powder, and stir with a high-speed stirrer at a stirring speed of 6000 r / min for 4 h;

[0045] ③ Centrifuge the slurry obtained in step ②, repeat 2 times, dry the wet material after removing the suspension, the drying temperature is 55°C, sieve the dried material, sieve it 3 times with a 100-mesh sieve, and then calcine the obtained powder in an oxygen atmosphere, at a heating rate of 5°C / min, at a calcination temperature of 800°C, and keep warm for 8h;

[0046] ④ Mix the Y2O3 powder obtained in step ③ with commercial high-purity 99.99% Al2O3 powder according to the stoichiometric ratio of Y3Al5O 12 Weighing, using anhydrous ethanol as solvent, polyethyleneimine as dispersant, the amount of dispersant added is 0.5wt.% of the total mass of Y2O3 powder and Al2O3 powder, adjusting the slurry mass solid content to 40wt.%, and then planetary ball milling, the planetary ball milling speed is 180r / min, the ball milling time is 30h, and then adding powdered PVB B-98 with a total mass of 6wt.% of Y2O3 powder and Al2O3 powder, and continuing ball milling for 15h;

[0047] ⑤ The slurry obtained in step ④ is subjected to spray granulation, the granulation atomization speed is 8000r / min, the hot air temperature is 90°C, and Y2O3-Al2O3 spherical powder is obtained; it is sieved using a 200-mesh sieve to obtain a high-fluidity powder;

[0048] ⑥ Calcine the powder obtained in step ⑤ in an air environment at a temperature of 1020° C. for 8 hours, dry grind the powder using alumina grinding balls, and then sieve the powder to a 100-mesh size for 3 times; then classify the powder using an ultrasonic vibrating screen, and take powder above 325 mesh for subsequent plasma spraying;

[0049] ⑦ The powder obtained in step ⑥ is prepared into a suspension, the solid content of the suspension is 13 vol.%, and ammonium polyacrylate is used as a dispersant, and the amount of the dispersant added is 1.0 wt.% of the powder mass;

[0050] ⑧ The suspension obtained in step ⑦ is used for plasma spraying to obtain a plasma sprayed product. The plasma spraying process is as follows: the spraying gas is a composite gas mixed with argon, nitrogen and hydrogen, the ratio of argon: nitrogen: hydrogen is 6:2.5:1.5, the total gas intake volume is 250slpm, the spraying current is 280A, the atomizing gas flow rate is 60ml / min, and the spray gun moving speed is 800mm / s.

[0051] Example 3

[0052] ① Commercial high-purity 99.99% micron Y2O3 powder is prepared into a slurry with a volume solid content of 15.0 vol.%, and a polyacrylic acid anion dispersant is used. The amount of the dispersant added is 0.5 wt.% to 2.0 wt.% of the Y2O3 powder mass, and then planetary ball milling is performed. The ball milling medium is alumina grinding balls, the ball milling jar is made of high-purity alumina ball milling jars, the solvent is deionized water, the ball milling speed is 250 r / min, and the ball milling time is 40 h;

[0053] ② Centrifuge the slurry obtained in step ① at a centrifugal speed of 2800 r / min for 6 min, remove the suspension, then add deionized water with a mass percentage of 28 wt.% of Y2O3 powder, and stir with a high-speed stirrer at a stirring speed of 5000 r / min for 3 h;

[0054] ③ Centrifuge the slurry obtained in step ②, repeat 2 times, dry the wet material after removing the suspension, the drying temperature is 55°C, sieve the dried material, sieve it 3 times with a 100-mesh sieve, and then calcine the obtained powder in an oxygen environment, at a heating rate of 4°C / min, at a calcination temperature of 700°C, and keep warm for 7h;

[0055] ④ Mix the Y2O3 powder obtained in step ③ with commercial high-purity 99.99% Al2O3 powder according to the stoichiometric ratio of Y3Al5O 12 Weighing, using anhydrous ethanol as solvent, polyethyleneimine as dispersant, the amount of dispersant added is 0.3wt.% of the total mass of Y2O3 powder and Al2O3 powder, adjusting the slurry mass solid content to 38wt.%, and then planetary ball milling, the planetary ball milling speed is 170r / min, the ball milling time is 25h, and then adding powdered PVB B-98 with a total mass of 5wt.% of Y2O3 powder and Al2O3 powder, and continue ball milling for 14h;

[0056] ⑤ The slurry obtained in step ④ is subjected to spray granulation, the granulation atomization speed is 8000r / min, the hot air temperature is 88°C, and Y2O3-Al2O3 spherical powder is obtained; it is sieved using a 200-mesh sieve to obtain a high-fluidity powder;

[0057] ⑥ The powder obtained in step ⑤ was calcined in an air environment at a temperature of 1010°C for 6 hours, and the powder was dry-milled using alumina grinding balls, and then sieved with a 100-mesh sieve for 3 times; then the powder was graded using an ultrasonic vibrating sieve, and powders above 325 mesh were taken for subsequent plasma spraying;

[0058] ⑦ The powder obtained in step ⑥ is prepared into a suspension, the suspension volume solid content is 12 vol.%, and ammonium polyacrylate is used as a dispersant, and the amount of the dispersant added is 0.8 wt.% of the powder mass;

[0059] ⑧ The suspension obtained in step ⑦ is used for plasma spraying to obtain a plasma sprayed product. The plasma spraying process is as follows: the spraying gas is a composite gas mixed with argon, nitrogen and hydrogen, the ratio of argon: nitrogen: hydrogen in the mixed gas is 7:2:1, the total gas intake volume is 220slpm, the spraying current is 260A, the atomizing gas flow rate is 50ml / min, and the spray gun moving speed is 700mm / s.

[0060] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a YAG transparent ceramic suspension for plasma spraying, characterized in that: The following steps are involved: ① Prepare a slurry with commercial high-purity 99.99% micron Y2O3 powder, the solid content of which is 14.0 vol.% to 16.0 vol.%, add a polyacrylic acid anion dispersant, and then perform ball milling; ② Centrifuge the slurry obtained in step ① to remove the suspension, add deionized water, and stir using a high-speed stirrer; ③ Centrifuge the slurry obtained in step ② twice, dry the wet material after removing the suspension, sieve and calcine; ④ Mix the Y2O3 powder obtained in step ③ with commercial high-purity 99.99% Al2O3 powder according to the stoichiometric ratio of Y3Al5O 12 Weigh, use anhydrous ethanol as solvent, polyethyleneimine as dispersant, adjust the slurry mass solid content to 35wt.%~40wt.%, ball mill for 15h~30h, then add 3wt.%~6wt.% PVB of the total mass of Y2O3 powder and Al2O3 powder, and continue ball milling for 12h~15h; ⑤ The slurry obtained in step ④ is subjected to spray granulation, the granulation atomization speed is 8000r / min, the hot air temperature is 85℃~90℃, and Y2O3-Al2O3 spherical powder is obtained; sieve to obtain high fluidity powder; ⑥ Calcine the powder obtained in step ⑤, dry grind the powder, and sieve it; then use an ultrasonic vibration screen to classify it, and take powder above 325 mesh for subsequent plasma spraying; ⑦ The powder obtained in step ⑥ is prepared into a suspension having a solid content of 10 vol.% to 13 vol.%, and ammonium polyacrylate dispersant is added to obtain the product.

2. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: In step ①, the amount of dispersant added is 0.5wt.% to 2.0wt.% of the Y2O3 powder mass, the planetary ball milling medium is alumina grinding balls, the ball milling jar material is a high-purity alumina ball milling jar, the solvent is deionized water, the ball milling speed is 200r / min to 280r / min, and the ball milling time is 36h to 48h.

3. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: In step ②, the centrifugal speed is 2400r / min~3000r / min, the centrifugal time is 5min~8min, the amount of deionized water added is 25wt.%~30wt.% of the mass of Y2O3 powder, the mixer speed is 4000r / min~6000r / min, and the stirring is 2h~4h.

4. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: The drying temperature in step ③ is 55°C, the sieving is performed using a 100-mesh sieve 3 times, the calcination process is performed in an oxygen environment, the heating rate is 3-5°C / min, the calcination temperature is 600°C-800°C, and the heat preservation is performed for 6h-8h.

5. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: The amount of dispersant added in step ④ is 0.1wt.% to 0.5wt.% of the total mass of Y2O3 powder and Al2O3 powder, the planetary ball mill speed is 160r / min to 180r / min, PVB is a low viscosity type, model B-98, and is in powder form.

6. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: The sieving in step ⑤ uses a 200-mesh sieve.

7. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: The calcination environment in step ⑥ is an air environment, the calcination temperature is 1000°C to 1020°C, the temperature is kept for 4h to 8h, and the grinding is performed using alumina grinding balls, the sieve mesh number is 100 mesh, and the sieving is performed 3 times.

8. The method for preparing a YAG transparent ceramic suspension for plasma spraying according to claim 1, characterized in that: The amount of the dispersant added in step ⑦ is 0.5wt.% to 1.0wt.% of the powder mass.

9. Use of the suspension obtained by the preparation method according to any one of claims 1 to 8 in plasma spraying, characterized in that: The plasma spraying process is as follows: the spraying gas is a mixture of argon, nitrogen and hydrogen, the total gas intake volume is 180-250slpm, the spraying current is 200A-280A, the atomizing gas flow rate is 30-60ml / min, and the spray gun moving speed is 500-800mm / s.

10. The use according to claim 9, characterized in that: The ratio of argon: nitrogen: hydrogen in the mixed gas is 5+x:4-xy:1+y, wherein: 1≤x≤3, 0≤y≤0.5, and argon, nitrogen and hydrogen are introduced synchronously.

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